Timecodes

Timecode support. More...

Macros
#define	LQT_TIMECODE_DROP   0x0001
	Indicates whether the timecode is drop frame.
#define	LQT_TIMECODE_24HMAX   0x0002
	Indicates whether the timecode wraps after 24 hours.
#define	LQT_TIMECODE_NEG_OK   0x0004
	Indicates whether negative time values are allowed.
#define	LQT_TIMECODE_COUNTER   0x0008
	Indicates whether the time value corresponds to a tape counter value.

Functions
void	lqt_add_timecode_track (quicktime_t *file, int track, uint32_t flags, int framerate)
	Attach a timecode track to a video track.
void	lqt_write_timecode (quicktime_t *file, int track, uint32_t timecode)
	Write a timecode for the next video frame to be encoded.
int	lqt_has_timecode_track (quicktime_t *file, int track, uint32_t *flags, int *framerate)
	Check, if a video track has timecodes.
int	lqt_read_timecode (quicktime_t *file, int track, uint32_t *timecode)
	Read the timecode for the next frame to be decoded.
const char *	lqt_get_timecode_tape_name (quicktime_t *file, int track)
	Get the tape name stored in a timecode track.
void	lqt_set_timecode_tape_name (quicktime_t *file, int track, const char *tapename)
	Set the tapename for a timecode track.
int	lqt_get_timecode_track_enabled (quicktime_t *file, int track)
	Get the enabled flag of a timecode track.
void	lqt_set_timecode_track_enabled (quicktime_t *file, int track, int enabled)
	Enable or disable a timecode track.

Detailed Description

Timecode support.

Timecodes are passed to/from libquicktime in the same format as they are stored in the file: 32 bit unsigned integers. For the meaning of the bits, see the section "Timecode Sample Data" in the Quicktime file format specification.

Macro Definition Documentation

LQT_TIMECODE_DROP

#define LQT_TIMECODE_DROP   0x0001

Indicates whether the timecode is drop frame.

LQT_TIMECODE_24HMAX

#define LQT_TIMECODE_24HMAX   0x0002

Indicates whether the timecode wraps after 24 hours.

LQT_TIMECODE_NEG_OK

#define LQT_TIMECODE_NEG_OK   0x0004

Indicates whether negative time values are allowed.

LQT_TIMECODE_COUNTER

#define LQT_TIMECODE_COUNTER   0x0008

Indicates whether the time value corresponds to a tape counter value.

Function Documentation

lqt_add_timecode_track()

void lqt_add_timecode_track	(	quicktime_t *	file,
		int	track,
		uint32_t	flags,
		int	framerate )

Attach a timecode track to a video track.

Parameters

file	A quicktime handle
track	Video track index (starting with 0)
flags	Zero or more of the LQT_TIMECODE_* flags
framerate	The integer framerate

If the format (e.g. AVI) doesn't support timecode, this function emits a warning.

Since 1.1.0

References lqt_add_timecode_track().

Referenced by lqt_add_timecode_track().

lqt_write_timecode()

void lqt_write_timecode	(	quicktime_t *	file,
		int	track,
		uint32_t	timecode )

Write a timecode for the next video frame to be encoded.

Parameters

file	A quicktime handle
track	Video track index (starting with 0)

Call this function before encoding the actual video frame.

Since 1.1.0

References lqt_write_timecode().

Referenced by lqt_write_timecode().

lqt_has_timecode_track()

int lqt_has_timecode_track	(	quicktime_t *	file,
		int	track,
		uint32_t *	flags,
		int *	framerate )

Check, if a video track has timecodes.

Parameters

file	A quicktime handle
track	Video track index (starting with 0)
flags	If non NULL returns zero or more of the LQT_TIMECODE_* flags
framerate	If non NULL returns the integer framerate

Returns

1 if timecodes are available, 0 else

Since 1.1.0

References lqt_has_timecode_track().

Referenced by lqt_has_timecode_track().

lqt_read_timecode()

int lqt_read_timecode	(	quicktime_t *	file,
		int	track,
		uint32_t *	timecode )

Read the timecode for the next frame to be decoded.

Parameters

file	A quicktime handle
track	Video track index (starting with 0)
timecode	Returns the timecode if available

Returns

1 if a timecode is available for this frame, 0 else

For frames, which have no timecode attached, you can increment the last timecode accordingly in your application. Call this function before decoding the actual video frame.

Since 1.1.0

References lqt_read_timecode().

Referenced by lqt_read_timecode().

lqt_get_timecode_tape_name()

const char * lqt_get_timecode_tape_name	(	quicktime_t *	file,
		int	track )

Get the tape name stored in a timecode track.

Parameters

file	A quicktime handle
track	Video track index (starting with 0)

Returns

pointer to tape name (might be NULL if no tape name)

Returned pointer should remain valid as long as the file is open. Do not free it.

Since 1.1.0

References lqt_get_timecode_tape_name().

Referenced by lqt_get_timecode_tape_name().

lqt_set_timecode_tape_name()

void lqt_set_timecode_tape_name	(	quicktime_t *	file,
		int	track,
		const char *	tapename )

Set the tapename for a timecode track.

Parameters

file	A quicktime handle
track	Video track index (starting with 0)
tapename	Tape name string

A copy is made of the string passed in

Since 1.1.0

References lqt_set_timecode_tape_name().

Referenced by lqt_set_timecode_tape_name().

lqt_get_timecode_track_enabled()

int lqt_get_timecode_track_enabled	(	quicktime_t *	file,
		int	track )

Get the enabled flag of a timecode track.

Parameters

file	A quicktime handle
track	Video track index (starting with 0)

Returns

1 if enabled, 0 if not enabled

Since 1.1.0

References lqt_get_timecode_track_enabled().

Referenced by lqt_get_timecode_track_enabled().

lqt_set_timecode_track_enabled()

void lqt_set_timecode_track_enabled	(	quicktime_t *	file,
		int	track,
		int	enabled )

Enable or disable a timecode track.

Parameters

file	A quicktime handle
track	Video track index (starting with 0)
enabled	0=>disable otherwise enable

Since 1.1.0

References lqt_set_timecode_track_enabled().

Referenced by lqt_set_timecode_track_enabled().